Question

我的应用程序中有两个模型，CompanyUk和CompanyName。 CompanyUk hasmany CompanyNames。 Activerecord正在创建CompanyUk.CompanyNames，但它找不到任何CompanyNames。这是代码：

class CompanyName < ActiveRecord::Base
  belongs_to :CompanyUk, :foreign_key => "company_number"
end

class CompanyUk < ActiveRecord::Base

  has_many :CompanyNames, :dependent => :destroy, :foreign_key => "company_number"

  validates_presence_of :company_number, :reg_office, :type, :incorporation_date #, :next_accounts_date, :next_return_date # should eventually have these

  validates_uniqueness_of :company_number, :case_sensitive => false

  validates_associated :CompanyNames

  set_inheritance_column :kind
end

class CreateCompanyUks < ActiveRecord::Migration
  def self.up
    create_table :company_uks do |t|
      t.string :company_number, :null=>false
      t.text :reg_office, :null=>false
      t.string :type, :null=>false
      t.string :business_nature
      t.string :status
      t.date :incorporation_date, :null=>false
      t.date :last_accounts_date
      t.date :next_accounts_date
      t.date :last_return_date
      t.date :next_return_date

      t.primary_key :company_number

      t.timestamps
    end
  end
end



class CreateCompanyNames < ActiveRecord::Migration
  def self.up
    create_table :company_names do |t|
      t.string :company_number, :null=>false
      t.string :name, :null=>false
      t.date :date_adopted, :null=>false

      t.timestamps
    end
  end
end

数据库的内容：

irb(main):011:0> CompanyUk.all
=> [#<CompanyUk id: 1, company_number: "12345", reg_office: "Example office", type: "Private company limited by shares", business_nature: nil, status: nil, incorporation_date: "2011-05-28", last_accounts_date: nil, next_accounts_date: nil, last_return_date: nil, next_return_date: nil, created_at: "2011-05-28 09:47:19", updated_at: "2011-05-28 09:47:19">]

irb(main):012:0> CompanyName.all
=> [#<CompanyName id: 1, company_number: "12345", name: "foo ltd", date_adopted: "2011-05-28", created_at: "2011-05-28 09:47:19", updated_at: "2011-05-28 09:47:19">, #<CompanyName id: 2, company_number: "12345", name: "foo ltd", date_adopted: "2011-05-28", created_at: "2011-05-28 10:09:29", updated_at: "2011-05-28 10:09:29">, #<CompanyName id: 3, company_num
ber: "1", name: "foobar ltd", date_adopted: "2011-05-28", created_at: "2011-05-28 0:10:52", updated_at: "2011-05-28 10:10:52">]

尽管有多个CompanyNames：

irb(main):009:0> CompanyUk.all.first.CompanyNames
=> []

此外，通过CompanyUk.CompanyNames创建新的CompanyName不会正确设置CompanyNumber（CompanyUk的主键和关系上设置的外键）。

那么，有什么方法可以解决这个问题吗？或者更好的参考模型和协会如何运作？

Answer 1

是否有违反惯例的特殊原因？

例如：这：

has_many :CompanyNames, :dependent => :destroy, :foreign_key => "company_number"

......应该是：

has_many :company_names, :dependent => :destroy

......只要迁移是：

class CreateCompanyNames < ActiveRecord::Migration
  def self.up
    create_table :company_names do |t|
      t.belongs_to :company_uk, :null=>false
      t.string :name, :null=>false
      t.date :date_adopted, :null=>false

      t.timestamps
    end
  end
end

在Rails 3中使用迁移和关联的指南：

http://guides.rubyonrails.org/migrations.html

http://guides.rubyonrails.org/association_basics.html

请注意，Rails在很大程度上依赖约定优于配置来制作Just Work（TM）。违反这些惯例，除非确实有必要，否则经常会引起头疼：）

Rails“magic”加入不起作用 - activerecord找不到链接表条目

1 个答案: